Alesis MicAmp ????

[ksor]

Does any of you know the pin configuration of 2X8 pin connector on this module - see pictures (in the next postings too !)

IF I can get knowledge of the pin configuration, can I then use this module as a pre-amp for mics to my LINE inputs ?

 

[ksor]

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[ksor]

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[ksor]

No one have anything to say ?

 

[gemini86]

Xlr connectors, some resistors and some quad opamps...should be pretty simple to trace out a schematic in about half an hour. Start by doing this, then maybe somebody will have something to say. I don't see any means of gain control, so these probably went right to faders. I'm guessing it's a high impedance output, will very little current drive, so you'll only be able to connect to high impedance inputs.

May not be worth the time, probably better of buying an art or behinger preamp over spending money on that thing.

 

[ksor]

It ain't THAT simple because the PCB is dobble sided and it's hard to de-solder (maybe a new word - I don't know the right term !) the XLR's - I thought maybe somebody knew the module - but nobody knows ;-(( !

 

[gemini86]

It's not a popular, nor legacy module, so doubtful anyone here would have the schematic. Try emailing alesis! They just may come through for you.

 

[solderspongebob]

I would x-ref the datasheet for the opamps and find out which pins are for power. First trace these back from an op-amp to the pin header and then apply a suitable power source. Then I would just feed an input into the first XLR and probe around the pin header until I find a signal; make a note of which pin then move onto the next XLR, and so on so forth. Judging by the number of pins there's probably 8 unbalanced outputs, at least one ground pin and either single or dual power rails.

 

[ksor]

I would x-ref the datasheet for the opamps and find out which pins are for power. First trace these back from an op-amp to the pin header and then apply a suitable power source. Then I would just feed an input into the first XLR and probe around the pin header until I find a signal; make a note of which pin then move onto the next XLR, and so on so forth. Judging by the number of pins there's probably 8 unbalanced outputs, at least one ground pin and either single or dual power rails.

Yeah, you'r quite right - the pin connector is THE ONLY connection to "the outside og the module", and with that amount of pins it CAN'T be for 8 BALANCED outputs - so it's not even worth going on with that peace of junk !

Thx for opening my eyes !

I'll just dis-mount the XLR's an reuse them some time.

 

[PRR]

> 2X8 pin connector

2x6

You know there are four audio outputs plus 3 or 4 power and ground pins. I can _see_, from here, two pins doubled-up also leading all around the board. I bet that's ground (signal and power). 2x6=12. Minus 4 for power/grnd is 8. Four channels with 8 pins suggests 2 pins per channel. I can clearly see the traces run to Ch2 and Ch3. They run under the chips, but your meter will quickly tell if they hit a chip-pin from behind. The MC33079 datasheet will tell what that pin is.

I don't see any urge to desolder the XLRs.

 

[ksor]

I simply DON'T want to use it when it's not BALANCED - and it COULDN'T be ... so I'll just re-use the XLR's !

(maybe you mean they isn't worth it ;-))

 

[gemini86]

I simply DON'T want to use it when it's not BALANCED - and it COULDN'T be ... so I'll just re-use the XLR's !

(maybe you mean they isn't worth it ;-))

it's got 8 inputs, so probably unbalanced...

Guess what though, unbalanced doesn't automatically mean GARBAGE... Lot's of great records have been made on unbalanced gear. If you're running a small or home studio (small meaning, less than a basketball court sized sound stage) then you can run unbalanced, 10k all day long with minimal problems (keep power cords away from audio cables). Balanced low impedance outputs are useful when running cable lengths > 100 feet. In my little one-room studio, I could use a single mic cable to run across the room.

determine what it is that you NEED, and then go forward with fulfilling that need. Need a preamp on the cheap? buy one. Need a really great clean/amazing sounding preamp for less than you could buy a "big name brand"? Build it.